Add more playback rates for MPV

Model/Player/Backends/AVPlayerBackend.swift

@@ -21,6 +21,14 @@ final class AVPlayerBackend: PlayerBackend {
     var stream: Stream?
     var video: Video?
 
+    var suggestedPlaybackRates: [Double] {
+        [0.5, 0.67, 0.8, 1, 1.25, 1.5, 2]
+    }
+
+    func canPlayAtRate(_ rate: Double) -> Bool {
+        suggestedPlaybackRates.contains(rate)
+    }
+
     var currentTime: CMTime? {
         avPlayer.currentTime()
     }

Model/Player/Backends/MPVBackend.swift

@@ -92,6 +92,14 @@ final class MPVBackend: PlayerBackend {
     internal var controlsUpdates = false
     private var timeObserverThrottle = Throttle(interval: 2)
 
+    var suggestedPlaybackRates: [Double] {
+        [0.1, 0.25, 0.3, 0.33, 0.5, 0.67, 0.8, 1, 1.25, 1.5, 1.75, 2, 3, 4]
+    }
+
+    func canPlayAtRate(_ rate: Double) -> Bool {
+        rate > 0 && rate <= 100
+    }
+
     var tracks: Int {
         client?.tracksCount ?? -1
     }

Model/Player/Backends/PlayerBackend.swift

@@ -6,6 +6,7 @@ import Foundation
 #endif
 
 protocol PlayerBackend {
+    var suggestedPlaybackRates: [Double] { get }
     var model: PlayerModel! { get }
     var controls: PlayerControlsModel! { get }
     var playerTime: PlayerTimeModel! { get }
@@ -30,6 +31,7 @@ protocol PlayerBackend {
 
     func bestPlayable(_ streams: [Stream], maxResolution: ResolutionSetting) -> Stream?
     func canPlay(_ stream: Stream) -> Bool
+    func canPlayAtRate(_ rate: Double) -> Bool
 
     func playStream(
         _ stream: Stream,

Model/Player/PlayerModel.swift

@@ -47,7 +47,6 @@ final class PlayerModel: ObservableObject {
 
     static var shared: PlayerModel!
 
-    static let availableRates: [Double] = [0.5, 0.67, 0.8, 1, 1.25, 1.5, 2]
     let logger = Logger(label: "stream.yattee.app")
 
     var avPlayerView = AppleAVPlayerView()
@@ -499,6 +498,9 @@ final class PlayerModel: ObservableObject {
         let fromBackend: PlayerBackend = from == .appleAVPlayer ? avPlayerBackend : mpvBackend
         let toBackend: PlayerBackend = to == .appleAVPlayer ? avPlayerBackend : mpvBackend
 
+        if !self.backend.canPlayAtRate(currentRate) {
+            currentRate = self.backend.suggestedPlaybackRates.last { $0 < currentRate } ?? 1.0
+        }
         self.backend.didChangeTo()
 
         if wasPlaying {

Model/Player/PlayerTVMenu.swift

@@ -59,7 +59,7 @@ extension PlayerModel {
         }
 
         private var rateMenuActions: [UIAction] {
-            PlayerModel.availableRates.map { rate in
+            PlayerModel.shared.backend.suggestedPlaybackRates.map { rate in
                 let image = currentRate == rate ? UIImage(systemName: "checkmark") : nil
 
                 return UIAction(title: rateLabel(rate), image: image) { _ in